The Arch to Arc is billed as the hardest triathlon in the world. It is comprised of a 87 mile run from Marble Arch in London to Dover, a swim across the Channel to Calais, finishing with a 180 mile bike ride to the Arc de Triomphe in Paris. Paul Parrish, 49, a recovering alcoholic, is the oldest man to have completed the race, doing so in a time of 84 hours 44 minutes. He is among over 20 people to have completed the event.